Everything Your Poop Schedule Says About Your Health

There is no single “normal” number of times to poop a week – it can range from three times a day to three times a week, says the NHS.

But a 2025 study, which involved 1,400 adults, found there is a “Goldilocks [or ‘just right’] zone” for poop frequency, which is once to twice a day.

The study authors divided participants into four poop frequency groups:

• Constipated (one or two bowel movements per week),
• Low-normal (between three and six bowel movements per week),
• High-normal (between one and three bowel movements per day), and
• Diarrhoea (more than three bowel movements a day).

Then, they looked at health markers in each group, including gut microbiomes and blood samples.

The scientists found that people whose gut microbiomes had more fibre-fermenting gut bacteria, which is often associated with good gut health, tended to poop once or twice a day.

But bacteria linked to protein-related gut fermentation were likely to be stronger in those with constipation or diarrhoea.

These, the researchers said, might release “toxins” into the body.

“If stool sticks around too long in the gut, microbes use up all of the available dietary fibre, which they ferment into beneficial short-chain fatty acids. After that, the ecosystem switches to fermentation of proteins, which produces several toxins that can make their way into the bloodstream,” the study’s lead author, Johnson-Martinez, said.

And a build-up of these “toxins,” including indoxyl sulphate or trimethylamine, may be linked to kidney disease and cardiovascular disease.

Meanwhile, those with diarrhoea had more C-reactive proteins, a sign of chronic inflammation, and chemicals that may be linked to liver damage.

“In a generally healthy population, we show that constipation, in particular, is associated with blood levels of microbially derived toxins known to cause organ damage, prior to any disease diagnosis,” study author Dr Sean Gibbons said.

In this research, people who adhered to a “Goldilocks zone” schedule tended to eat a lot of fibre, exercise regularly, and stay hydrated.

Speaking to BBC Science Focus, Dr Gibbons added: “High-protein diets can also be kind of dangerous because of the protein fermentation by-products I mentioned.

“There’s a lot of evidence, especially in younger people, that they can be problematic for things like type-2 diabetes”.